A file containing the personal details of almost 10,000 people in detention was accessed in 16 countries, including China, Egypt, Malaysia, Pakistan and Russia, raising further concerns that asylum seekers returned to their countries of origin or their families may be at risk of persecution.

The breach could place asylum seekers and their families at risk if they are identified by the authorities in their country of origin. A report by management consultants KPMG found that widespread internal failures in the immigration department led to the breach occurring.

The potentially global access shows the file could have been copied thousands of times since the breach occurred. It is not known how many times the personal details of asylum seekers were accessed within the file.

The document was also accessed in the United States, Canada, Fiji, India, South Korea and several of the downloads came from anonymised locations.

The department has redacted the IP addresses and details of network owners who downloaded the file. They have also redacted information on whether the files can be tracked and recovered from the individuals who downloaded them.

The worldwide access to the document raises serious concerns about the prospect of returning asylum seekers home. The immigration department has been sending letters to asylum seekers facing removal, giving them just 14 days to put their concerns about the breach in writing.

The Greens senator Sarah Hanson-Young called on the government to rule out returning asylum seekers exposed in the breach.

“This departmental error has put thousands of people’s lives at further risk. It is simply unacceptable and those affected must be offered the protection they deserve,” she said.

“The Abbott government must rule out returning these people to the extreme danger that now faces them.”

At a media conference with the prime minister on Thursday the immigration minister, Scott Morrison, was asked whether the revelation of countries where the file was downloaded could have any ramifications for the processing of claims.

Morrison said: “Not necessarily. Every single individual case of a person’s asylum claim is assessed on its individual merits, and any factors that are relevant to that assessment are taken into account and the extent to which those matters may be relevant will be considered at that time.

“There have already been a number of those cases where that issue has been raised and it has been dismissed.”

The Mercury reported on Wednesday that Vietnamese asylum seekers named in the breach were taking legal action to attempt to halt their deportations.

Following the release of the KPMG report the department said: “The department has taken action to implement the recommendations in that report and ensure that this sort of incident does not happen again. The department deeply regrets inadvertently allowing unauthorised access to personal information.”

The new KPMG documents also flag the risk that the data breach may have extended far beyond the file containing the personal details.

The report said the limited knowledge of online publishing standards “creates a significant risk that other publications may not have been properly reviewed and published and therefore, would be at risk of having underlying data issues. The same would apply to any electronically transmitted information, not just online publishing.”

Daniel Webb, the director of legal advocacy at the Human Rights Law Centre, said the revelations in the document were “more evidence of the scale of the breach and the gravity of risk that flows from it”.

“The breach is something that should be factored into every single person’s protection claim who has been affected by it.”

The immigration minister, Scott Morrison, announced that Thursday marked "a significant milestone" for the federal government in that it has been six months since there has been a successful people smuggling venture to Australia. However, "The threat continues; we remain ever vigilant … but we have always believed in these policies, that they would work"